A method of solid phase extraction/gas chromatography-mass spectrometry was developed for the simultaneous determination of 23 organochlorine pesticides in soil.And different matrix effect compensation approaches were studied.Soil samples were extracted with n hexane-acetone(1∶1

by volume)

then purified with a florisil column

and finally detected by GC-MS.Medium or strong matrix effects existed in 7 organic chlorines

which was controlled within 20% for all the 23 organochlorines when 10 mL dichloromethane∶n-hexane(1∶9

by volume) and 10 mL acetone∶n hexane(1∶9

by volume) were selected as the eluents of solid phase extraction

and the pulse pressure was set at 275.8 kPa.Results showed that there was a good linear relationship of the method in the concentration range of 04-10 μg·mL-1 with correlation coefficients(r2) no less than 0.999 2.The limits of detection and limits of quantitation were in the ranges of 1.0-8.6 μg·kg-1 and 4.0-34.4 μg·kg-1

respectively.The average recoveries for blank soil at spiked levels of 20

60 and 100 μg·kg-1 ranged from 46.3% to 109%

with relative standard deviations(RSDs

n=6) of 0.68%-15%.Five organochlorine pesticides

including α-BHC

γ-BHC

p

p′-DDE

endrin aldehyde

p

p′-DDT were detected in a soil sample.